linux-rng/kernel, branch master

Merge tag 'locking-urgent-2026-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2026-08-30T16:57:35Z

Pull locking fix from Ingo Molnar: - Revert a commit to spinlock cleanup guards that got caught up in the subtle limitations & fragility of guards (again...) and caused a regression (Peter Zijlstra) * tag 'locking-urgent-2026-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: locking: Revert switching guards to _irq_{disable,enable}()

Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

2026-08-30T16:22:00Z

Pull tracing fixes from Steven Rostedt: - Fix error output of boot instance creation failure Currently if a boot instance creation fails, instead of printing out the name of the instance that failed, it prints "(null)". That is because it prints "cur_str" that had already been processed by strsep(). Print the saved name instead. While at it, print the error code of the failure. - Fix use-after-free for same named historgrams Histograms can be named so that they can be used in multiple events. But if the named histogram has a variable attached, the second event that uses the named histogram which duplicates it and needs to free the original after duplication leaves the old variable in place and still visible. If another histogram uses than variable, it will use the stale one which will try to reference the freed duplicate histogram and crash the kernel. Free the duplicate variables along with the duplicated histogram data. - Check return value of kthread_run() in event self test The events self tests uses a kthread for testing but does not check if it succeeded in creating a kthread. If the kthread creation were to fail, the code will still try to call kthread_stop() on the error returned. - Fix race between reading trace_pipe and updating subbuffer size If a user is reading the trace_pipe file at the same time they update the ring buffer sub-buffer size, can cause the trace_pipe read to read stale data. Add trace_access_lock() around updating the ring buffer sub-buffer size. - Fix eventfs_inode on failure path in creation of the events directory In the creation of the "events" directory, if after allocating the eventfs_inode a failure is detected, it calls cleanup_ei() which calls free_ei(). The free_ei() will test if eventfs_inode being freed has no children. It is a bug if it does. But on the failure case of the creation of the "events" directory, the children lists have not yet been initialized and the free will trigger a warning because list_empty() on an uninitialized list returns false. Move the initialization into init_ei() where it makes more sense and makes sure that a created eventfs_inode has its lists initialized upon creation. - Check return value of kthread_run() in ftrace direct sample code The sample code that shows how to use the ftrace direct calls does not test the return of kthread_run() to see if it succeeds. Return a failure if the kthread_run() doesn't succeed. - Clear user events state on fork in case of alloc failure On fork, the child gets a pointer to the parent's user events state. It makes a copy of it then updates the child's pointer to it. But if the allocation fails, the duplication function leaves the child with a pointer to its parent's descriptor. When the child cleans up its data, it will free the parent's descriptor while the parent is still using it. In the duplication function, set the child's user_event_mm to NULL before testing if the allocation succeeded, and when it exits it will not free the parent's descriptor. - Fix retry exhaustion in simple ring buffer reader swap simple_ring_buffer_swap_reader_page() starts with retry set to 8 and post-decrements it only after a failed link replacement. On the final attempt, a successful replacement leaves retry at zero, while a failed replacement leaves it at -1. But the check for success expects the retry value to be non-zero and exits with an error on zero. This is the opposite result. Fix it. - Fail nicely when the remote swap_reader_page() returns an error Currently, if the swap_reader_page() of a remote buffer fails, it triggers a WARN_ON_ONCE() and continues normally. Instead, have it exit with an error and a pr_warn() print instead of a full WARNING. * tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: ring-buffer: Stop remote reader update when page swap fails tracing: Fix retry exhaustion in simple ring buffer reader swap tracing/user_events: Clear copied tracing state before fork duplication samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify eventfs: Initialize ei->children and ei->list in init_ei() tracing: Fix use-after-free in trace_pipe read on sub-buffer order change tracing: Fix crash passing ERR_PTR to kthread_stop() tracing: Fix use-after-free with same-name named triggers tracing: Fix logged instance name on creation failure

ring-buffer: Stop remote reader update when page swap fails

2026-08-28T01:31:51Z

The remote swap_reader_page callback can return -EBUSY when the writer moves the head before the remote catches it, particularly during an event storm on a small buffer. __rb_get_reader_page_from_remote() currently warns about that failure but continues with the unchanged reader ID and rearranges the local page list as though the swap succeeded. Handle the callback failure as a recoverable error. Report it with pr_warn_ratelimited() and return NULL. Callers already handle a NULL reader page as a failed attempt. This avoids splicing the same page as both the previous and new reader without flooding the log under contention. Cc: stable@vger.kernel.org Fixes: 2e67fabd8b77 ("ring-buffer: Introduce ring-buffer remotes") Link: https://patch.msgid.link/20260825-kernel-patch-1-v2-2-bb3461807a32@gmail.com Assisted-by: LLM sparse Signed-off-by: Ivan Immanuel Shaji Signed-off-by: Steven Rostedt

tracing: Fix retry exhaustion in simple ring buffer reader swap

2026-08-28T01:31:41Z

simple_ring_buffer_swap_reader_page() starts with retry set to 8 and post-decrements it only after a failed link replacement. On the final attempt, a successful replacement leaves retry at zero, while a failed replacement leaves it at -1. The current !retry test reverses both outcomes. It returns an error after a successful final replacement, leaving the link update complete but the reader bookkeeping unfinished. After a failed final replacement, it falls through and updates the head and reader pointers as though the replacement succeeded, which can corrupt the ring. Treat only a negative counter as exhaustion and return the documented -EBUSY error. Cc: stable@vger.kernel.org Fixes: 34e5b958bdad ("tracing: Introduce simple_ring_buffer") Link: https://patch.msgid.link/20260825-kernel-patch-1-v2-1-bb3461807a32@gmail.com Assisted-by: LLM sparse Reviewed-by: Vincent Donnefort Signed-off-by: Ivan Immanuel Shaji Signed-off-by: Steven Rostedt

tracing/user_events: Clear copied tracing state before fork duplication

2026-08-28T01:30:22Z

dup_task_struct() copies user_event_mm from the parent into the child, without grabbing a reference to it. user_event_mm_dup() should replace it, but it leaves that copied pointer unmodified if user_event_mm_alloc() fails. When the child exits, user_event_mm_remove() decrements a reference the child never owned, which ultimately frees user_event_mm, while the parent still as a stale pointer to it. This creates a UAF, which KASAN reports as: BUG: KASAN: slab-use-after-free in current_user_event_mm+0x51/0x1d0 Write of size 4 at addr ffff888005010d30 by task init/44 Call Trace: kasan_report+0xce/0x100 kasan_check_range+0x10f/0x1e0 current_user_event_mm+0x51/0x1d0 user_events_ioctl+0x82e/0x15c0 __x64_sys_ioctl+0x139/0x1c0 do_syscall_64+0xce/0x450 entry_SYSCALL_64_after_hwframe+0x77/0x7f Allocated by task 44: __kasan_kmalloc+0x8f/0xa0 __kmalloc_cache_noprof+0x180/0x3a0 user_event_mm_alloc+0x3c/0x1f0 current_user_event_mm+0x88/0x1d0 Freed by task 42: __kasan_slab_free+0x43/0x70 kfree+0x13a/0x390 process_one_work+0x696/0xf90 worker_thread+0x420/0xba0 The fix simply clears the copied pointer before any possible failure. In case of failure, the child then has nothing to free. Cc: stable@vger.kernel.org Fixes: 7235759084a4 ("tracing/user_events: Use remote writes for event enablement") Link: https://patch.msgid.link/20260827184321.2964601-2-Jeremy.Jean@oss.cyber.gouv.fr Assisted-by: Codex:gpt-5 Signed-off-by: Jérémy Jean Reviewed-by: Bradley Morgan Signed-off-by: Steven Rostedt

Merge tag 'dma-mapping-7.3-2026-08-27' of git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux

2026-08-27T19:14:19Z

Pull dma-mapping fix from Marek Szyprowski: - integer overflow fix for kernel cmdline parser for DMA contiguous initialization code (Alexander Graf) * tag 'dma-mapping-7.3-2026-08-27' of git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux: dma-contiguous: fix truncation of numa_cma / cma_pernuma sizes >= 2G

Merge tag 'mm-stable-2026-08-26-15-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2026-08-27T16:17:06Z

Pull more MM updates from Andrew Morton: - "mm/rmap: index MAP_PRIVATE file-backed folios by anonymous pgoff" (Lorenzo Stoakes) Index MAP_PRIVATE file-backed folios by their anonymous page offset to resolve confusion around reverse mapping for zeroed and CoW'd file-backed memory. Use this new VMA anonymous page offset tracking to eliminate index conflicts and lay the foundation for scalable CoW performance improvements. - "promote mapped executable folios after first usage for MGLRU" (Baolin Wang) Make MGLRU's protection of mapped executable file folios more reliable. Follow the classical LRU's logic, promoting mapped executable file folios after their first usage to give executable code a better chance to stay in memory and improve workload performance. - "mm: vmscan: fix node reclaim ignoring swappiness parameter" (Ridong Chen) Fix per-node proactive reclaim interface's ignoring the swappiness parameter when CONFIG_MEMCG is disabled by consolidating sc_swappiness() into a single function that checks proactive_swappiness regardless of kernel configuration. - "mm/vmscan: reduce lru_lock contention via vmstat-derived scan-balance cost" (Usama Arif) Reduce lru_lock contention in the reclaim path by deriving scan-balance costs from vmstat counters rather than lock-acquired producer updates. Read and decay these cost signals on the reclaim side under a dedicated per-lruvec lock, reducing total LRU lock wait time by over 60% without impacting scan throughput. - "zram: fix zram issues reported by sashiko" (Sergey Senozhatsky) Fix two low-risk zram bugs which Sashiko spotted in drive-by review. - "Honor XA_FLAGS_ACCOUNT in xas_split_alloc() and charge to folio's memcg" (Zi Yan) Fix xas_split_alloc() by enabling target folio memcg charging during splits and adding the missing __GFP_ACCOUNT flag for proper XArray node memory accounting. - "selftests/mm: use pattern matching in .gitignore" (Pratyush Mallick) Replace hardcoded binary names in selftests/mm/.gitignore with a generic pattern-matching rule to automatically ignore generated test files and avoid manual updates when adding new tests. - "mm/page_ext: remove pgdat_page_ext_init()" (Sang-Heon Jeon) Make the incompatibility between FLATMEM and NUMA explicit in mm/Kconfig and remove the unused pgdat_page_ext_init() function. - "zram: fix zstd error paths and add parameter validation" (Haoqin Huang) Clean up zram compression backends by removing redundant error cleanup, adding parameter and dictionary validation, auto-prefixing algorithm error logs, and resetting parameters prior to reinitialization. - "zram: fix stale scan bounds after reinitialization" (Longlong Xia) Prevent out-of-bounds slot accesses during concurrent zram resets by moving table scan bound calculations under dev_lock in writeback_store() and read_block_state(). - "add anon mTHP collapse test cases" (Baolin Wang) Extend selftests helper functions to support arbitrary page orders and add new test cases and options for mTHP collapse in khugepaged. - "selftests/mm: Handle unsupported and transient test conditions" (Muhammad Usama Anjum) Update MM selftests to report a SKIP status instead of a failure when required kernel or filesystem features are unsupported, while adding retry logic for transient page migration errors. - "mm/zswap: Fixes and improves the zswap shrink" (Hao Jia) Fix the missing zswap global shrinker when CONFIG_MEMCG is disabled and extend shrink_memcg() to support batch writeback for improved writeback efficiency. - "alloc_tag: introduce IOCTL-based filtering for MAP" (Suren Baghdasaryan) Introduce an IOCTL-based binary interface for memory allocation profiling that enables kernel-side filtering before per-CPU counter aggregation. This eliminates the text-parsing overhead of /proc/allocinfo and provides up to a 20x speedup by transferring only filtered allocation data to userspace. - "better block swap batching and a different take on swap_ops v5" (Christoph Hellwig) Refactor block swap I/O to use swap_iocb for batching instead of single-bio requests and rebase the swap_ops interface, achieving faster swap throughput during kernel builds. - "mm: kmemleak: reduce transient false positives by confirming leaks" (Catalin Marinas) Reduce false-positive kmemleak reports by combining two kmemleak enhancements that add a second confirmation scan and a configurable minimum unreferenced scan count module parameter. - "mm: kmemleak: default min_unref_scans to 2 for verbose kernels" (Breno Leitao) Auto-scanning kernels can generate false-positive memory leak reports on single scans, so this patch defaults min_unref_scans to 2 when CONFIG_DEBUG_KMEMLEAK_VERBOSE is enabled to require a second confirming scan. - "swap_ops updates" (Christoph Hellwig) Batching I/O for synchronous swap devices causes performance regressions and filesystem-based swap suffers from double-indirection overhead. This series resolves both issues by reintroducing per-folio writes for synchronous swap and allowing filesystems to directly export their own swap_ops. - "mm/khugepaged: several cleanups" (Nico Pache) khugepaged accumulated redundant state-checking patterns and outdated comments following mTHP integration. Introduce dedicated helpers for PTE validation and event counting while refreshing the internal documentation. - "maple_tree: lock checking and clean ups" (Liam Howlett) Syzbot reports incorrectly blame memory management exit paths for locking bugs, maple tree erase operations risk allocation failures without gfp flags and internal documentation lacks clarity. Improve lock error detection, update docs, fix race and allocation edge cases and optimize erase allocations using a fallback to GFP_KERNEL | GFP_NOFAIL. * tag 'mm-stable-2026-08-26-15-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (172 commits) selftests/proc: make proc-maps-race work with READ_IMPLIES_EXEC memcg: move LRU size accounting on reparenting instead of copying it mm/vmscan: fix comment logic in balance_pgdat maple_tree: add helper mas_make_walkable() maple_tree: avoid extra gap calculation maple_tree: fix argument name in header maple_tree: change two GFP flags in tests maple_tree: document erase and allocations better maple_tree: avoid mas_erase() and mtree_erase() failures maple_tree: document that erase may use GFP_KERNEL for allocations maple_tree: catch race in mas_alloc_cyclic() maple_tree: add bulk parent set helper maple_tree: micro optimisation of mas_wr_store_type() maple_tree: optimise mas_wr_node_store() when not in rcu mode maple_tree: use prefetched value in mas_wr_store_type() maple_tree: clarify comments on mas_nomem() maple_tree: drop MAPLE_ALLOC_SLOTS maple_tree: drop dead code from mas_extend_spanning_null() maple_tree: documentation fix maple_tree: add write lock checking with lockdep sequence numbers ...

Merge tag 'nfs-for-7.3-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

2026-08-26T22:09:21Z

Pull NFS client updates from Trond Myklebust: "Highlights include: Stable fixes: - Use-after-free fixes for the sunrpc client code - Delegation hash table leak - NULL dereference on lockowner allocation failure - Fix a handshake completion race in the TLS code - Fix an error sign checking issue when deciding whether the pNFS layout is still in use, or can be returned - Fix a layout segment leak in pnfs_layout_process() Other bugfixes: - Fix a missing NULL check in the rpcbind client - annotate shared socket callbacks with READ_ONCE/WRITE_ONCE - nfs_inode_set_delegation() error paths should return the delegation - Use clear_and_wake_up_bit() in nfs_clear_invalid_mapping() and the pNFS code. - Fix the nfs4_alloc_client() error paths to free the IDR allocation - fix folio dereference before NULL check in nfs_inode_remove_request() - Fix delayed delegation return - Fix another state manager race with umount - Fix device leaks on parse failure - Avoid cancelling in-flight I/O during a layout recall if the server doesn't require it - flexfiles: report cancelled I/O as a layout error - flexfiles: fix NULL dereference for NFSv4.0 data servers - Fix incorrect argument passed to nfs4_delete_lease() - Fix several symlink issues resulting from nfs_atomic_open_v23() - Fix an uninitialised variable issue in the NFSv4.1 callback code - fix LAYOUTSTATS send buffer exhaustion Features and cleanups: - NFSv4.2: Allow the server to specify that file data may not be cached - localio: optimise I/O submission when when not doing memory reclaim - localio: Remove duplicate wait code in nfs_local_commit - flexfiles: support loosely coupled NFSv4.x data servers - pNFS: key the data server cache on the NFS version" * tag 'nfs-for-7.3-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (33 commits) NFSv4.1: fix layout segment leak on the pnfs_layout_process() forget path NFSv4/pnfs: key the data server cache on the NFS version NFSv4.2: fix LAYOUTSTATS send buffer exhaustion pNFS: Fix EBUSY check in pnfs_layout_need_return NFSv4.1: zero referring call lists before decoding nfs: fix ENXIO on O_CREAT open of existing symlink over NFSv3 SUNRPC: wait for in-flight client TLS handshake callback NFSv4: Fix incorrect argument passed to nfs4_delete_lease() in nfs4_add_lease() lockd: fix NULL dereference on lockowner allocation failure NFS: fix delegation_hash_table leak when nfs4_server_common_setup() fails NFSv4/flexfiles: support loosely coupled data servers NFSv4/flexfiles: fix NULL dereference for NFSv4.0 data servers NFSv4: pin the superblock for active state owners sunrpc: fix use-after-free in __rpc_clnt_handle_event and __rpc_clnt_remove_pipedir NFS/localio: issue commit inline when not in a memory-reclaim context NFS/localio: remove dead FLUSH_SYNC handling from nfs_local_commit NFS/localio: issue IO inline when not in a memory-reclaim context NFS: Fix delayed delegation return list handling NFS: Verify symlink inode before caching target NFS: fix folio dereference before NULL check in nfs_inode_remove_request() ...

Merge tag 'pm-7.3-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

2026-08-26T21:13:26Z

Pull more power management updates from Rafael Wysocki: "These fix two issues in the intel_rapl power capping driver, fix a potential issue in the schedutil cpufreq governor on 32-bit systems, fix a runtime PM issue related to failing system suspend, and update the intel_pstate cpufreq driver: - Fix a kernel panic during PMU unbind in the intel_rapl power capping driver and sign-extend the PMU delta on counter wraparound in it to avoid misreporting energy (Sumeet Pawnikar and Yifan Li) - Unblock runtime PM when device prepare fails that was not done by mistake (Shibo Zhu) - Fix possible rate limit overflow on 32-bit systems in the schedutil cpufreq governor (Hui Su) - Consolidate HWP P-states initialization in the intel_pstate cpufreq driver and make that driver avoid using the DESIRED_PERF HWP hint when the Dynamic Efficiency Control (DEC) is enabled in the processor to avoid inconsistent behavior (Rafael Wysocki)" * tag 'pm-7.3-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: powercap: intel_rapl: Fix kernel panic during PMU unbind PM: sleep: Unblock runtime PM when device prepare fails powercap: intel_rapl: Sign-extend the PMU delta on counter wraparound cpufreq: intel_pstate: Avoid using DESIRED_PERF when DEC is enabled cpufreq: intel_pstate: Consolidate HWP P-states initialization cpufreq: schedutil: Fix rate limit overflow

Merge branches 'pm-cpufreq' and 'pm-sleep'

2026-08-26T17:49:23Z

Merge additional cpufreq updates and one update related to system sleep for 7.3-rc1: - Unblock runtime PM when device prepare fails that was not done by mistake (Shibo Zhu) - Fix possible rate limit overflow on 32-bit systems in the schedutil cpufreq governor (Hui Su) - Consolidate HWP P-states initialization in the intel_pstate cpufreq driver and make that driver avoid using the DESIRED_PERF HWP hint when the Dynamic Efficiency Control (DEC) is enabled in the processor to avoid inconsistent behavior (Rafael Wysocki) * pm-cpufreq: cpufreq: intel_pstate: Avoid using DESIRED_PERF when DEC is enabled cpufreq: intel_pstate: Consolidate HWP P-states initialization cpufreq: schedutil: Fix rate limit overflow * pm-sleep: PM: sleep: Unblock runtime PM when device prepare fails